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Appendix VI.

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between the guides so formed, being lifted by the board i:>, which
passes between the friction rollers EE. The rollers are driven by
separate pullies F F, one with a crossed and the other with an
open strap, the rotation being always such as to cause the tup-
board to rise. The brackets G G contain the bearings, the back
pair s being fixed, while the front form eccentric bearings that
can be rotated by the lever Q so as to release the frictional grip
between the rollers and the board. The releasing gear is auto-
matic, and consists of an adjustable tappet H, which is caught by
the tup on the upstroke, thus causing the rod j K to be lifted,
and the lever Q rotated so far as to permit the tup and its board
to fall. The hand lever L is for the same purpose, and is princi-
pally convenient for plain forging, where a succession of light
blows may be required. To keep the tup in a raised position,
the catch lever p is supplied, and the depression of rod M by the
foot lever N permits the tup to again fall freely.

CHAPTER V,

JP. 166. Universal Radial Drill.—The description of
the usual form of radial drill at p. 166 will serve as an intro-
duction to the universal form shewn in Fig. 930. In the latter

/%. 930